Attachment plug



Apr. 117, 1923.

-' S. M CLATCHIE ATTACHMENT PLUG Filed Sept. 2, 1919 Qwventoz Patented Apr. l'l', i923.

STANLEY MOCLATCHIE, 0F CAMBRIDGE, ASEIGNOR TO THE COIN- NECTICU'I' ELECTRIC MANUFACTURING CQMPANY, OF BRIDGEPOBT, CONNECTICUT,

A CORPORATION OF CONNECTICUT.

ATTACHMENT PLUG.

Application filed September To all whom it may concern:

Be it known that I, STANLEY h loCnArorrin, a citizen of the United States, residing at Cambridge, in the county of Middlesex and State of Massachusetts, have invented new and useful Improvements in Attachment Plugs, of which the following is a specification.

My invention relates to attachment plugs, and has for its object improved and simplified features of construction.

The drawings show a plug embodyingmy invention in one form. Figure 1 is an end elevation of the main body portion of the plug, the outer shell which threads into the socket being removed. Fig. 2 is a section of the complete plug taken on the line 2-2 of Fig. 1. Fig. 3 is a section of the complete plug taken on the line 3-3 of Fig. 1. Fig. t is an end view of the outer shell alone. Figs. 5 and 6 are side elevations of the body of the plug with the outer shell removed, the former showing the right hand side of the plug as positioned in Fig. 3, and the latter showing the left hand side, and Fig. 7 is a side elevation of the plug with a portion of the shell broken away to show the method of securing one of the terminal wires.

In the form shown iny plug has a one piece insulating body 1, having a hand-hold at its lower end, a middle portionadapted to slip into a threaded. socket shell, and a reduced upper end portion containing a cen ter terminal post. The threaded socket shell, indicated in the drawings by the numeral :2, has an inner flange which fits down on the shoulder 5 formed. at the base of the reduced upper portion of the body. A threaded eyelet 6 is riveted in a recess in one side of the body. A binding-screw 7 passes thru a hole 8 located in the above mentioned flange, and is threaded into this eyelet. The flange is intended to bind down and establish connection with one of the conductor terminals T, and the screw 7 serves to bind the flange down as required and, furthermore, to hold the shell as a whole in position. Instead of an eyelet riveted in place, as l have here shown, a nut might be employed, cemented in a suitable recess or a threaded bushing might be moulded into the insulating body; other like forms carrying out the spirit of my invention may suggest themselves. itliowever, the form shown ofiers the advan ,ing it to the transverse wire passage.

2, 1919. Serial No. 321,088.

tage of being simple and efi'ective. The eyelet is provided with head at one end, and it is only necessary to slip it into a recess suitably moulded. in the side of the body an d to spread the other end in the manner indicated in Fig. 1. A countersink is provided for the end to spread into, and the eyelet is so fixed in place. The countersink and corresponding spreading shown in Fig. 1 are oval in form owing to space limitations. The head of the eyelet is best made rectangular in order to keep it from turnin The center terminal post consists of the embed ded metal part 9, containing the longitudinal binding-screw 4t and the transverse wire terminal passage 10. The screw 41- is partially exposed so as to serve as the center socket contact of the plug. The portion of the post thru which runs the transverse passage may be enlarged to form a head, as shown. The head, and the opening in which it is fitted, should be made polygonal in order to prevent the post from turning. The part is fixed in place by riveting over the end opposite the head, as shown. A neat appear ance is given the plug by having the riveted end together with part of the head of the screw l disappear in a countersink in the body, as indicated in Figs. 2 and By this construction a center binding terminal is provided in which the wire end T and all unsightly portions are concealed. The arrangement is at once neat and simple, and moreover the wire is restrained from pulling out by the bends which are involved in leady 3 it will be seen that the body contains an enlarged central opening 11, having leading from it the oppositely disposed radial openings 12 and 13. These radial passages communicate at the surface of the body with the grooves 1 and 15, which are adapted to severally receive the two cord terminals. The grooves are shown in perspective in Figs. 5 and 6. Groove 15 leads to the shoulder 5. Groove 14 leads to a hole which communicates with the terminal wire passage 10. The threaded shell is covered on the inside by insulation in the region of passages 12 and i l. This insulation may take the form of a sheet otinsulating material as shown at 3 in Figs. 2 and 3, or it may consist simply oi a coat of enamel on the inner surface of the shell. ll: insulating material. is

used it is preferably glued or shellac-ked to the inside of the shell.

The operation of wiring the plug is as follows: With the outer shell removed the two terminals of the conducting cord are introduced in the opening 11. One terminal is leadthru the radial opening 12, and then laid along the groove 14; its bared end is then doubled over and inserted in the wire passage 10, and finally is bound down by means of the binding-screw 4. Contact be tween any stray port-ions of the conductor and the outer shell is prevented by the insulation covering 3. The remaining cord terminal is lead thru the passage 13 and along the groove 15; its bared end is then laid around on the shoulder 55, in such man ner asto pass over the edge of the eylet 6.'

The outer shell is now put on and secured in place by means of the binding-screw 7. It is evident that the last mentioned cord end will be bound securely and in electrical connection with the shell when the screw 7 has been driven into place.

The design here set forth provides a simple and inexpensive one-piece attachment plug. The passages are so placed that they may be readily adapted to easy moulding in porcelain or composition, and are at the same time made to accommodate cord terminals of equal length and to restrain the same from pulling out by flexing them sharply before binding. The terminal binding-posts are simple and neatly disposed of. Ample insulation is provided.

It is evident that features of my invention could readily be applied in constructions of other general form than that here shown, and I do not limit myself to the particular combination, just described.

I claim as my invention:

1. An attachment plug comprises a unitary insulating body provided with a center contact, a shoulder, aside contact comprising a screw shell having an inwardly extending flange adapted to engage over said shoulder, wire terminals. one of which is adapted to rest freely on said shoulder beneath said flange, a threaded member-seated in said shoulder, and a screw adapted to be received in said member to bind said flange against said wire terminal and secure said shell on the body.

2. An attachment plug comprising a unitary insulating body provided with an external annular shoulder and a reduced end portioneXtending therebeyond, and having a central bore for the reception of lead wires with passages extending. laterally therefrom, a center contact in said reduced end portion, a screw shell side contact en.

gaged over the major portion of the bony and having an inwardly extending flange engaged over said shoulder, an eyelet in said shoulder, lead wires one of which rests on the shoulder beneath said flange, and a screw to be received in said eyelet for binding the flange against the shoulder.

3. An attachment plug comprising a unitary insulating body having an opening to receive lead wires and two lateral passages leading therefrom, the outer surface of said body having grooves therein communicating with said lateral passages, center and side contacts adapted to receive lead wires. said body being provided with a shoulder ad jacent said side contact, said lead wires adapted to enter said grooves and one of said grooves extending into the shoulder, and a screw for securing said side contact to the shoulder and binding said contact against one of said lead wires; p

4-. An attachment plug comprising an insulating body provided with a shoulder. a center contact. a side contact comprising a screw shell having an inwardly extending flange adapted to engage over said shoulder, said body being provided with a longitudinal passage and circuitous passages leading from the longitudinal passage to the con tacts, lead wires in said passages one of which is connected to the center contact and one adapted to rest freely on the shoulder beneath the flange, and means to bind said flange against said wire and secure the shell to the body. the bends in the passages being arranged to relieve the contacts of the greater part of external strain on the lead wires.

5. An attachment plug comprising an insulating body, a center contact, a side contact comprising a screw shell, said body being provided with a longitudinal passage an d circuitous passages leadin from the longitudinal passage to the contacts, said latter passages including grooves in the outer surface of the body, lead wires in said passages leading to said contacts, and means for securing the side contact to the body over the grooves in the outer surface thereof, the bends in the passages being arranged to relieve the contacts of the greater part of external strain on the lead wires.

Cambridge, Massachusetts, July 17, 1919.

In witness whereof, I have hereunto subscribed my name in the presence of two witnesses.

STANLEY MCCLATCHIE.

Witnesses SrnNon BURTON, K NNETH ABBOTT VIALL. 

